1. Field of the Invention
The present invention relates to an image evaluation chart, and more particularly to an image evaluation chart for efficiently testing all performances, for example, resolution, balance, view angle, distortion, and focus, etc., of video equipment such as a camera by means of one-shot image capture, and a method for testing performances of the video equipment using the same.
2. Description of the Related Art
Presently, an inspector visually tests performances of video equipment such as a camera. In more detail, the inspector separately tests individual electronic components such as a lens and a sensor, and checks operations of a complete product with his or her naked eye.
For the convenience of description and better understanding, an example of a conventional image evaluation chart is shown in FIG. 1, and a method for testing performance of video equipment using the conventional image evaluation chart is shown in FIG. 2.
The conventional method for testing performance of video equipment such as a camera will hereinafter be described with reference to FIGS. 1˜2. A chart 5 is inserted between a projector 1 and a lens 3, and light from the projector 1 is projected on a wall 2 spaced apart from the lens 3 by a predetermined distance.
The light projected by the projector 1 is focused on a wall via the chart 5 and lens 3, such that a prescribed shape of the chart 5 is shown on the wall 2.
The prescribed shape of the conventional chart 5 is classified into a center display area A, eight first display areas B circularly surrounding the center display area A while being spaced apart from the center display area A by a predetermined distance, eight second display areas C circularly surrounding the first display areas B while being spaced apart from the first display areas B by a predetermined distance, and four third display areas D circularly surrounding the second display areas C while being spaced apart from the second display areas C by a predetermined distance.
Each display area includes eight inspection areas P denoted by “a”, “b”, “c”, “d”, “e”, “f”, “g”, and “h” in FIG. 1 showing a partially enlarged view of one display area. The inspection area “a” is the largest one of the eight inspection areas P, and the inspection area “h” is the smallest one of the eight inspection areas P. That is, the inspection area is gradually reduced in alphabetical order from a to h. An image resolution can be tested using the eight inspection areas.
If the above-identified shape of the chart 5 is focused on the wall 2 after passing through the lens 3 by means of the projector 1, the inspector recognizes a resolution of the lens 3 by visually checking the an image displayed on the wall 2. Provided that all the inspection areas “a” to “h” are visually recognized by the inspector's naked eye, it is determined that the image focused on the wall has a high resolution. Provided that a plurality of inspection areas from “a” to either “d” or “e” are visually recognized by the inspector's naked eye, it is determined that the image focused on the wall has a medium resolution. Provided that any one of either the inspection area “g” or the inspection area “h” cannot be visually recognized by the inspector's naked eye, it is determined that the image focused on the wall has a low resolution.
As stated above, the inspector has visually recognized the resolution of the lens while viewing the image focused on the wall with his or her naked eye.
However, the aforementioned performance test method has a disadvantage in that the inspector cannot acquire a correct performance value when visually checking the resolution of video equipment. In more detail, because individual inspectors take a subjective view of accuracy of a focus, it is impossible for each inspector to acquire a correct performance value such that resultant data is unreliable.
Further, the aforementioned performance test method allows individual electronic components, for example, a lens and a sensor, etc., to be tested separately from each other, resulting in a delayed test speed and deteriorated working efficiency.